The present invention relates to a touch sense interface and to a method for controlling a touch sense interface. More particularly, the present invention relates to a multiple finger touch sense interface for transmitting resistance perceptions and weight perceptions to fingertips.
A touch sense interface has been proposed in the prior art that transmits a resistance perception and a weight perception to the hand or to a single point, such as a fingertip, when contacting an object in virtual space. Examples of such touch sense interfaces include the serial-link PHANTOMTM™ of SensAble Technology, Inc. (USA, homepage http://www.Sensable.com/) and the parallel-link Haptic Master of Nissho Electronics Corporation. Although these interfaces may transmit touch senses to one location, it is difficult to transmit touch senses to multiple fingertips (multiple points).
Research has been conducted to transmit touch senses to two fingertips with two serial-link touch sense interfaces, as described in Tsuneo Yoshikawa and Akihiro Nagura, “A Touch and Force Display System for 3D Haptic Interface” (Japan Virtual Reality Academy Thesis Magazine, Vol. 3, No. 3, pp. 75–82, 1998). However, the movable range of the proposed interfaces is extremely limited.
The usage of the above interfaces decreases the awkwardness and burden of operation. However, touch sense interfaces that have a wide operating space and transmit force perceptions at multiple points have not been proposed.
To transmit the forces of multiple points, a touch sense interface has been proposed that incorporates a force feedback mechanism, which is attached to the hand or arm of a person. The following are two examples of such interface.
1. Force Feedback Glove (H. Kawasaki and T. Hayashi, “Force Feedback Glove for Manipulation of Virtual Objects, Journal of Robotics and Mechatronics,” Vol. 5, No. 1, pp. 79–84, 1993)
2. CyberGrasp ™ of Immersion Corporation (USA, homepage http://www.immersion.com/)
These interfaces transmit force to multiple fingertips of a person. However, since the interfaces are not connected to mechanical arms, it is difficult to transmit the perception of weight of a virtual object. Further, since the touch sense interface is attached to the hand or arm of a person, the person may feel constrained and the interface may feel heavy.
To transmit the weight perception of a virtual object, the following two systems have been proposed, which attach an arm mechanism, in addition to a force feedback mechanism, to the hand.
1. 3D Interaction products of Immersion Corporation (USA)                2. Force Feedback Device (Naoki Suzuki, Asaki Hattori, and five others, Development of Virtual Surgery System With Sense of Touch, Japan Virtual Reality Academy Thesis Magazine, Vol. 3, No. 4, pp. 237–243, 1998)        
However, these systems also require a person to wear an arm mechanism and a fingertip force feedback mechanism. Thus, the person may feel constrained and operations may be awkward and burdensome.